1. Field of the Invention
The present invention relates to biochar and, in particular, to treated and/or processed biochar having enhanced physical and chemical properties that increase the usefulness, predictability and efficacy of the treated biochar for a variety of applications.
2. Related Art
Biochar has been known for many years as a soil enhancer. Biochar is defined by the International Biochar Initiative (“IBI”) as “a solid material obtained from thermochemical conversion of biomass in an oxygen-limited environment. Biochar can be used for a range of applications as an agent for soil improvement, improved resource use efficiency, remediation and/or protection against particular environmental pollution and as an avenue for greenhouse gas (GHG) mitigation. In addition, to be recognized as biochar, the material has to pass a number of material property definitions that relate both to its value (e.g., H/Corg ratios relate to the degree of charring and therefore mineralization in soil) and its safety (e.g., heavy metal content).”
Biochar is defined by the American Association of Plant Food Control Officials (“AAPFCO”) as “a solid material obtained from thermochemical conversion of biomass in an oxygen-limited environment (pyrolysis) containing at least 60% carbon. Feedstocks may be composed of crop residue, wood or other forest waste, and animal manures. Materials transported in salt water, painted, or treated with preservatives are not permitted. When listing biochar in an ingredient statement, the feedstock shall be designated by prefixing the term biochar with the feedstock from which it was produced; i.e. poultry litter biochar, green waste biochar, papermill biochar, etc. When more than one feedstock is involved, all feedstocks greater than 10% of the total volume are to be listed by decreasing volume.”
Biochar is created by the pyrolysis of biomass, which generally involves heating and/or burning of organic matter, in a reduced oxygen environment, at a predetermined rate. Such heating and/or burning is stopped when the matter reaches a charcoal like stage. The resulting biochar consists of various pieces of residual solid material full of crevices, pores and holes that help store water, microorganisms and other nutrients that promote plant growth. For purposes of this application, the resulting pyrolyzed biomass will be referred to as “raw or untreated biochar.”
Raw biochar, while known for its soil enhancing characteristics, does not always benefit soil and, depending upon the biomass from which the biochar is produced, could potentially be harmful to the soil, making it unsuitable for various types of crops or other productive uses. In particular, biochar can be detrimental, or even toxic, to 1) soil microbes involved in nutrient transport to the plant; 2) plants and 3) humans. Raw biochars derived from different biomass will have different physical and chemical properties and will behave quite differently. For example, raw biochar having pH levels too high, containing too much ash, too much of other inorganic materials which can cause toxicity at elevated levels, or containing toxins or heavy metal content too high can be harmful and/or have minimal benefit to the soil and the plant life it supports. Raw biochar can also contain unacceptable levels of residual organic compounds such as acids, esters, ethers, ketones, alcohols, sugars, phenyls, alkanes, alkenes, phenols, polychlorinated biphenyls or poly or mono aromatic hydrocarbons which are either toxic or not beneficial to plant or animal life.
While some attention has been focused on the use of raw biochar in conjunction with controlling and regulating the growth of plants and vegetation, e.g., crops, the commercial and widespread adoption of biochar as a soil amendment has not occurred. There are several reasons for these failures. As described above, biochar may be derived from varied and different sources. As a result, these materials have very inconsistent and unpredictable properties. These inconsistencies and lack of predictability make their use difficult and in many cases problematic. Jeffery et al. in Agriculture, Ecosystems, and Environment (2011) (“Jeffery”) compiled the results from several biochar field trials from around the globe. The trials show at best a modest improvement with biochar applications and the application rates required to achieve these modest results is significant. (See Jeffery, at page 175 and FIG. 1). Even more recently, Spokas et al. published Biochar: A Synthesis of Its Agronomic Impact beyond Carbon Sequestration, in the Journal of Environmental Quality (July 2012), which demonstrated the how untreated biochar may yield vastly different economic and agronomic results when added to soil, from strongly positive to strongly negative. See, also, Buss et al., Inherent organic compounds in biochar—Their content, composition and potential toxic effects, Journal of Environmental Management 156 (2015).
In Lehmann, et al, Biochar for Environmental Management (2006)(“Lehmann”) a pioneer researcher, Lehmann, is quoted about biochar that “ . . . variability is high and it is not yet clear under what soil and climatic conditions high or low yields can be expected.” (Lehmann, Chp. 12, at page 207) It is believed that these inconsistencies and lackluster outcomes are common among biochar work. Since most cannot produce biochar with predictable properties and outcomes, the use of these materials, e.g., biochar, can have limited, sporadic or little to no beneficial effect. In certain cases, the use may be problematic and detrimental, e.g., lower crop yield, and in some situations, increased mortality rate and/or death of the crops.
Currently, biochar has mostly been a scientific curiosity, not found wide spread use, not found large scale commercial application, and has been relegated to small niche applications. Prior to the present inventions, biochar having predictable, controllable, and beneficial results have not been obtained, thereby prohibiting large scale applications. In general, the art has focused on the failings, and problems, of biochars by attempting to better select or sort the starting material or to refine the pyrolysis or other processes used to make the untreated biochar, without identifying, controlling, or enhancing the properties of a biochar that make it effective. Typically, these attempts were done with the hope that increased process control, material selection and refinements would overcome the unpredictable nature, inconsistencies, and harmful effects found with existing biochars. It is believed that these attempts have been to a lesser or greater extent failures. A need remains for producing biochars that can be used in large scale applications and that have certain generally sustainable, controllable and/or particular physical and chemical properties known to have the highest positive impact on soils. This need is satisfied by the present invention.